title: Effects of intrusion combined with anterior retraction on apical root resorption.
abstract: This study evaluated the influence of intrusion mechanics combined with anterior retraction on root resorption of the maxillary incisors. A sample of 56 patients was divided into two groups: group 1 comprised 28 patients (12 females and 16 males), presenting with an increased overjet and deep overbite (6.48 and 4.78 mm, respectively) treated with reverse curve of Spee intrusion mechanics and group 2 comprised 28 patients (12 females and 16 males) with an increased overjet of 5.67 mm and a normal overbite of 1.12 mm. The initial mean ages for groups 1 and 2 were 13.41 and 13.27 years, respectively. Pre- (T1) and post- (T2) treatment periapical radiographs were used to evaluate root resorption. The groups were compared using the Mann-Whitney U-test. Correlation between root resorption and tooth movement was investigated with Spearman's correlation coefficient. The subjects in group 1 had statistically greater root resorption (P < 0.05) than those in group 2. The initial overbite severity and the amount of correction had significant positive correlations with root resorption (r = 0.324 and r = 0.320, respectively). The combination of anterior retraction with intrusive mechanics causes more root resorption than anterior retraction of the maxillary incisors alone.
authors.affiliation: Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, Brazil.
authors.forename: Décio Rodrigues
authors.initials: DR
authors.lastname: Martins
authors.forename: Douglas
authors.initials: D
authors.lastname: Tibola
authors.forename: Guilherme
authors.initials: G
authors.lastname: Janson
authors.forename: Fábio Rogério Torres
authors.initials: FR
authors.lastname: Maria
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000601:surgery; D016022:Case-Control Studies; D002508:Cephalometry / Q000379:methods; D002648:Child; D005115:Extraoral Traction Appliances; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007180:Incisor / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008311:Malocclusion, Angle Class I / Q000628:therapy; D008312:Malocclusion, Angle Class II / Q000628:therapy; D008437:Maxilla / Q000000981:diagnostic imaging; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D057887:Overbite / Q000145:classification / Q000628:therapy; D016300:Radiography, Bitewing; D012189:Retrospective Studies; D012391:Root Resorption / Q000145:classification / Q000000981:diagnostic imaging / Q000209:etiology*; D013997:Time Factors; D019227:Tooth Apex / Q000000981:diagnostic imaging / Q000473:pathology*; D014081:Tooth Extraction; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult